Muscular system - Anatomical terminology for healthcare professionals | Kenhub

Summary

This video, the fourth episode of the Kenhub series on anatomical terminology, dives into the muscular system, breaking down complex muscle-related terms. It explains how muscles are classified by type (skeletal, smooth, and cardiac) and explores key roots, prefixes, and suffixes used in medical terminology related to muscles. Viewers learn how muscle names reflect factors such as shape, size, and function, and they are introduced to concepts like isotonic and isometric contractions. The episode is designed to make understanding and mastering muscular terminology approachable for healthcare professionals.

Takeaways

• 💪 Muscular terminology can be challenging, but breaking down the terms into roots, prefixes, and suffixes makes it easier.
• 🦾 There are three types of muscle in the body: skeletal (voluntary movement), smooth (involuntary movement), and cardiac (heart).
• 🧠 My/o- is a key prefix related to muscles, such as in 'myalgia' (muscle pain) or 'myopathy' (muscle disease).
• ❤️ Muscles can be named based on various criteria, including shape, size, fiber direction, and their attachments to bones or tissues.
• 📏 Terms like 'isotonic' and 'isometric' describe different types of muscle contractions based on whether or not the muscle changes length.
• 🧬 Agonist muscles are the prime movers in a movement, while antagonists work in opposition to control the movement.
• 🧩 Muscle names can indicate the number of heads (e.g., biceps, triceps) or their location (e.g., temporalis over the temporal bone).
• 🏋️‍♂️ Terms like 'spasmo-' refer to muscle spasms, while '-trophy' indicates muscle growth or development, as in 'atrophy' or 'hypertrophy.'
• 🔄 Eccentric contractions lengthen the muscle under load, whereas concentric contractions shorten the muscle during a movement.
• 🎯 Understanding these terminologies makes it easier to grasp medical conditions and anatomical functions related to muscles.

Q & A

What are the three types of muscle found in the body?

The three types of muscle in the body are skeletal muscle, smooth muscle, and cardiac muscle. Skeletal muscle is attached to bones and is responsible for voluntary movement, smooth muscle controls involuntary movements like those in organs and vessels, and cardiac muscle is found in the heart and is also involuntary.

What is the root 'my/o-' and where does it come from?

'My/o-' comes from the Greek word 'mys,' which means muscle. It is used in terms like 'myalgia' (muscle pain) and 'myopathy' (muscle disease).

What is the difference between skeletal, smooth, and cardiac muscle?

Skeletal muscle is attached to bones and responsible for voluntary movement, smooth muscle controls involuntary movements of organs and vessels, and cardiac muscle is found in the heart, controlling involuntary contractions to pump blood.

How are muscles named based on shape? Give examples.

Muscles are named based on their shape. Examples include the trapezius (diamond-shaped), deltoid (triangular-shaped), and serratus anterior (saw-like shape).

What does 'rhabdomy/o-' refer to?

'Rhabdomy/o-' refers to skeletal or striated muscle. An example is 'rhabdomyosarcoma,' a malignant tumor of skeletal muscle.

What do 'tend/o-' and 'fasci/o-' refer to?

'Tend/o-' or 'tendin/o-' refers to tendons, such as in 'tendinitis' (inflammation of a tendon). 'Fasci/o-' refers to fascia, the connective tissue covering muscles, such as in 'fasciodesis,' a procedure to suture fascia.

What are the seven main criteria used to name muscles?

The seven main criteria for naming muscles are shape, size, orientation of fibers, action, number of heads or bellies, attachments, and location.

What is the difference between isotonic and isometric muscle contractions?

Isotonic contractions involve muscle length changing while maintaining constant tension (e.g., lifting a load), and isometric contractions involve muscle tension without any change in muscle length (e.g., holding a plank).

What is the function of an agonist muscle in movement?

An agonist muscle, or prime mover, is the muscle responsible for performing most of the work in a movement. For example, the biceps brachii is the agonist in elbow flexion.

What is hypertrophy and how does it relate to muscles?

Hypertrophy refers to the overdevelopment or growth of a muscle. It is often associated with muscle building due to exercise or other factors.

Outlines

00:00

💪 Introduction to Muscular Terminology

The paragraph begins with a humorous comparison between muscle building and learning muscle terminology, highlighting how complex understanding muscle terms can be. It introduces the episode as part of the Kenhub series on anatomical terminology, focusing on naming muscles based on roots, prefixes, and suffixes. The paragraph then explains the three main types of muscle: skeletal (responsible for voluntary movement), smooth (involuntary, related to organs and vessels), and cardiac (found in the heart). It introduces the Greek root 'my/o-' as key to understanding muscle-related terms like myalgia (muscle pain) and myocarditis (inflammation of the heart muscle). Additionally, other important terms related to muscle, such as 'leiomy/o-' for smooth muscle and 'rhabdomy/o-' for skeletal muscle, are explained.

05:01

🔍 Seven Criteria for Naming Skeletal Muscles

This section explains how skeletal muscles are named according to seven main criteria: shape, size, orientation, action, number of heads, attachments, and location. It uses specific examples such as the trapezius muscle (diamond-shaped) and deltoid muscle (triangular), and names derived from size like gluteus maximus and vastus lateralis. Other factors like muscle fiber direction (e.g., transverse, rectus), actions (e.g., flexor, extensor), the number of heads (biceps, triceps), and muscle attachments (e.g., sternohyoid) are also discussed. The paragraph concludes by explaining how location names indicate where a muscle is found (e.g., temporalis over the temporal region).

10:01

🛠 Understanding Muscle Function in Movement

This paragraph shifts focus to how muscles function during movement, introducing terms like agonist (prime mover), synergist (helper), and antagonist (opposer). The biceps brachii is used as an example of an agonist for elbow flexion, while the triceps brachii is its antagonist. The role of antagonists in controlling movement speed and force is highlighted. It then moves into explaining types of muscle contractions: isotonic (where muscles change length) and isometric (where muscles contract without changing length). Two types of isotonic contractions are detailed—concentric (muscle shortens) and eccentric (muscle lengthens). The plank exercise serves as an example of isometric contraction.

🧠 Clinical Terminology for Muscle Conditions

This final section introduces terms relevant in clinical settings, focusing on muscle conditions. It explains the prefix 'spasmo-', relating to muscle spasms, and words like 'spasmogenic' (causing spasms). The suffix '-trophy', meaning growth, is introduced through terms like 'atrophy' (wasting away of muscles) and 'hypertrophy' (overdevelopment of muscles). The paragraph also explains 'clonic', meaning rapid involuntary muscle contractions. It ends by encouraging viewers to test their knowledge based on the video, subscribe to the channel, and stay tuned for the next episode on cardiovascular terminology.

Keywords

💡My/o

My/o is a root term derived from the Greek word 'mys,' meaning muscle. It's fundamental to understanding various medical terms related to muscular conditions and functions. In the script, it appears in words like 'myalgia' (muscle pain) and 'myopathy' (disease affecting muscle tissue), illustrating how the root is frequently used in medical terminology concerning muscles.

💡Skeletal Muscle

Skeletal muscle is one of the three types of muscles found in the body, responsible for voluntary movements. As described in the video, skeletal muscles are attached to bones, and they are what most people picture when thinking about muscles. The script emphasizes its importance in understanding muscle terminology by showing how it's different from smooth and cardiac muscles.

💡Isotonic Contraction

Isotonic contraction is a type of muscle contraction where the muscle changes length while maintaining a constant tension. It is divided into concentric (muscle shortens) and eccentric (muscle lengthens) contractions. The video explains this concept using examples like lifting or lowering a heavy load, providing viewers with a practical understanding of how muscles function in everyday movements.

💡Agonist Muscle

An agonist muscle, also known as the prime mover, is the primary muscle responsible for executing a specific movement. In the example provided in the video, the biceps brachii muscle serves as the agonist during the flexion of the forearm at the elbow joint. Understanding the role of the agonist is crucial for comprehending how different muscles work together to produce movements.

💡Antagonist Muscle

An antagonist muscle is one that works in opposition to the agonist muscle, often controlling the speed or force of a movement. In the video, the triceps brachii is cited as the antagonist to the biceps brachii during the flexion of the forearm. This concept is key to understanding how muscle pairs work to create smooth and controlled motions in the body.

💡Fasci/o

Fasci/o refers to fascia, which is a connective tissue that covers muscles. The video uses the term to explain conditions like 'fasciodesis,' a surgical procedure involving the attachment or suturing of fascia to another fascia or tendon. Understanding this term helps in identifying the relationship between muscles and their surrounding structures.

💡Hypertrophy

Hypertrophy refers to the overdevelopment or increase in size of muscle tissue. The video mentions this term in the context of muscle growth, highlighting how it contrasts with atrophy (muscle wasting). This concept is relevant for those studying how muscles adapt and change in response to different levels of activity or stress.

💡Tendin/o

Tendin/o is a term that relates to tendons, the connective tissues that attach muscles to bones. In the video, this term is used in the example 'tendinitis,' which means inflammation of a tendon. Recognizing this root term helps in understanding various conditions and treatments related to the tendons, a crucial part of the muscular system.

💡Isometric Contraction

Isometric contraction is a type of muscle contraction where tension is generated without a change in muscle length, resulting in no movement. The video explains this concept using the example of a plank exercise, where the muscles exert force without visibly shortening or lengthening. This term is essential for understanding different ways muscles can work without producing movement.

💡Cardiac Muscle

Cardiac muscle is one of the three types of muscle found in the body and is exclusive to the heart. The video emphasizes that this muscle type is involuntary and that we have no control over it. It is crucial for understanding the muscular system since cardiac muscle has unique properties that differentiate it from skeletal and smooth muscles.

Highlights

Learning muscular terminology can be more challenging than building muscle.

This episode teaches how muscles are named by breaking down terms into roots, prefixes, and suffixes.

Three basic muscle types: skeletal, smooth (visceral), and cardiac muscle.

The root 'my/o-' comes from Greek and is used in terms like myalgia (muscle pain) and myopathy (muscle disease).

'Myo-' can also be a prefix in terms like myocarditis, meaning inflammation of the heart muscle.

'Leiomy/o-' refers to smooth muscle, such as in leiomyoma uteri, a benign tumor of uterine smooth muscle.

'Rhabdomy/o-' refers to skeletal muscle, as in rhabdomyosarcoma, a malignant tumor of skeletal muscle.

Muscles can be named based on their shape, like the trapezius (diamond-shaped) or deltoid (triangle-shaped).

Size is another naming criterion: examples include gluteus maximus (largest muscle), vastus lateralis, and latissimus dorsi.

Muscles are also named according to fiber orientation, such as transverse (perpendicular fibers) or rectus (parallel fibers).

Muscle names may describe their function, like flexor digiti minimi (flexor of the little finger) or masseter (the chewer).

Some muscle names reflect the number of heads or bellies, like biceps brachii (two heads) and quadriceps femoris.

Location and attachment can influence muscle names, such as temporalis (found in the temporal region) or sternohyoid (attached to sternum and hyoid bone).

Types of muscle contraction: isotonic (muscle length changes) and isometric (muscle length remains the same).

Isotonic contractions include concentric (muscle shortens) and eccentric (muscle lengthens), both crucial in different movements.

Transcripts

Some people think working out to build muscle is painful.

Well, they clearly never try learning how to master their terminology.

Because, let's face it.

Flexing your muscles for a selfie is easy.

Explaining what they're about – is not.

If you've been feeling like learning the terminology of the muscular system is as about as difficult

as lifting four hundred kilos off the ground, you're not the only one.

Well, relax.

Sweat no more.

You’re going to be smashing this one in no time.

Welcome back to the fourth episode of the Kenhub series ‘Anatomical Terminology for

Healthcare Professionals’ – getting buffed with muscular terminology.

So if you've watched the previous episodes of this series, you'll know that instead of

helping you memorize the name of every single muscle, we're teaching you about how they're

named.

We do that by breaking down anatomical terms into their main components – roots, prefixes,

and suffixes.

But before I get to the meaty terminological stuff, let's begin with the three most basic

terms about muscle, which are the three types of muscle found in the body.

Skeletal muscle is generally attached to bone and responsible for voluntary movement of

the body.

It’s probably what you picture when someone mentions muscle.

Smooth muscle generally deals with involuntary movements like those related to our organs

and vessels.

It’s also known as a visceral muscle.

The final group is cardiac muscle which, of course, is found in the heart.

We all know we have no voluntary control over what the heart does.

Now I want to throw in a few of those roots and prefixes we love so much, and this will

help you decipher terms about conditions and processes related to the muscular tissue.

Perhaps, the most important term related to muscle is my/o-, which comes from the Greek

‘mys’ for muscle.

It can be used as the root in words like myalgia, which is a term for muscle pain.

Another is myopathy, which is the general term used for a disease specifically affecting

muscle tissue.

Myo- can also appear as a prefix such as myocarditis – myo- referring to muscle, card referring

to the Greek word ‘cardia’ which means heart, and -itis which we learned before means

inflammation.

So, inflammation of the muscle of the heart.

It also pops up the term leiomy/o-.

‘Leio’ is the Greek term for smooth so leiomy/o- refers to smooth muscle, like in

leiomyoma uteri – benign tumor of uterine smooth muscle.

Rhabdomy/o- refers to skeletal or striated muscle such as rhabdomyosarcoma, which is

a malignant tumor of skeletal muscle.

Of course, we can't forget muscul/o- which comes from Latin and is where we get the term

muscle.

An easy example of this prefix is musculocutaneous, which means relating to both muscle and skin.

I’d like to also show you a few terms which do not necessarily refer directly to muscle,

but to their associated tissues.

Tend/o- or tendin/o-, of course, relates to the tendons.

For example, tendinitis is inflammation of a tendon.

Similarly, fasci/o- refers to fascia – a connective tissue covering muscles.

You may see in terms like fasciodesis which is a surgical procedure of attaching or suturing

fascia to other fascia or a tendon.

Of course, like with all systems of the body, the list for all possible prefixes and roots

is long, but if we manage to take a note of these, you've made a great, great start.

Alright, now that we've been introduced to some of the most common prefixes and roots

related to the muscular system, let's turn our attention to the terminology we'll encounter

when looking at skeletal muscles, in particular, how they are named and as we've been learning

in this series, it's all in the name, and muscles are no different.

Once you learn to decipher the parts of their terminology, you're going to see that there

are seven main criteria which can be coded into the name of a muscle.

The first of these which contribute to a muscle name is its shape – for example, the trapezius

muscle, ‘trapezion’ means diamond-shaped - and you can clearly see why on this muscle.

The deltoid muscle suggesting the triangular shape of the Greek letter ‘delta’ or the

serratus anterior muscle which get its name from the word ‘serrare’ which means saw

in Latin.

Our second characteristic determining muscle names is their size.

Yes, there is a reason your butt is called your gluteus maximus.

It’s the largest muscle of the body.

Other examples include the vastus lateralis muscle, the fibularis brevis, the adductor

longus, or the latissimus dorsi muscle.

Another criterion for naming muscles is according to the orientation or directions of your fibers.

For example, the transverse muscle of the tongue whose fibers run perpendicular to the

midline; the external oblique muscle which has its fibers arranged diagonally or at an

angle; or if you see rectus in a name of a muscle like the rectus abdominis, it will

have fibers roughly parallel to the midline, and before you ask, six-pack is not a technical

term for this muscle.

Muscles can also be named in accordance with what they do.

I won't bore you with every single action, but most of these are obvious, like the flexor

digiti minimi – flexor of the little finger – or the extensor hallucis brevis – extensor

of the big toe.

Not all are clear though.

For example, the risorius muscle which helps us to smile or the masseter which literally

means the chewer.

The name can also tell you about the number of heads or bellies it might have.

For instance, you know this one for sure, the biceps brachii muscle, which has two heads.

Other examples include the triceps brachii or quadriceps femoris.

Our second last criterion for muscle names are its attachments.

This means they get their names from bones, bone parts, or tissue they're attached to.

There are lots of examples like these such as sternohyoid muscle which attaches to the

sternum and the hyoid bone or the pubococcygeus muscle which extends between the pubic and

coccygeal bones.

And, finally, unsurprisingly, location also pops up in muscle names.

It can indicate the region a muscle is found in.

There are lots of examples of these.

For instance, we have the temporalis muscle found over the temporal region of the skull

or the intercostal muscles located between the rib bones of the thoracic cage.

The muscle name might also refer to its relative position to another muscle.

For example, flexor digitorum superficialis is more superficial than its counterpart,

the flexor digitorum profundus.

Ok, so, I think that more than covers what we need to know about muscle names.

You can learn more about each and every muscle of the body right now by checking out our

articles and atlas at kenhub.com and explore muscle names in a whole new light.

Now, time to move on to look at some terms which may be used to describe function of

a muscle relative to a specific movement.

For example, let's take the movement flexion of the forearm at the elbow joint.

Said to have an agonist or prime mover muscle which does most of the work.

In this case, it's the biceps brachii muscle which flexes the elbow joint.

An agonist can be aided by synergist muscles – syn- together, erg- means work which help

either by direct action or by stabilizing the joint involved in the movement.

The muscle or muscles which work in opposition to an agonist are known as antagonists.

In this case, it's the triceps brachii which extends the forearm at the elbow joint.

An antagonist is sometimes important in controlling the speed or force of the movement created

by an agonist muscle.

Regardless of the type or location of a muscle, they all have the exact same function – contract

and relax.

However, not all types of contraction are the same.

Let’s check out some terms which you might encounter describing this.

There are two main types of muscle contraction – isotonic and isometric – and they all

begin with the prefix iso- which means equal or constant.

The most familiar type is known as isotonic contraction where the root tonic comes from

the Greek ‘tonus’ which means tone or tension.

So, it means contraction of equal or constant tension.

This is where the length of a muscle changes against a constant load.

Isotonic contractions can be separated into two types – concentric contractions where

the muscle shortens due to the force of contraction being greater to the load placed upon it,

and eccentric contractions, on the other hand, which occurs when the load is greater than

the force of contraction.

This causes the muscle to lengthen instead.

So, even though the muscle is getting longer, it is still contracting.

You’ll see this when we are carefully lowering a heavy load.

Without it, the load would quickly drop to the floor causing injury.

The opposite type of contraction is called isometric contraction where a load is forcing

a muscle to exert force, but without any change in length of the muscle, therefore, no movement

occurs.

To understand this, just think of a good old plank exercise.

Here, we experience an increasing tension over time without change in the length of

the muscle.

Feel it burn!

This is clearly not my favorite thing to do in the world.

Okay, the final stretch – let's wrap this up with a few word elements that are especially

useful in a clinical setting.

First up is spasmo-, which as you might expect, refers to involuntary spasm or contraction

of muscle; spasmogenic – substance or condition which causes spasm.

Next is the suffix -trophy which is often used in reference to muscles and means growth

or development.

For example, atrophy refers to wasting away or regression of a muscle usually due to a

disorder or disuse.

Or hypertrophy, which can be used to describe the overdevelopment of a muscle.

And, finally, clonic which comes from the Greek term clonus meaning alternating involuntary

contraction and relaxation of muscle in rapid succession.

Wow!

That was quite a lot of information, right?

Hopefully, you feel a lot more confident deciphering the not-so-subtle code that is muscular system

terminology.

It also brings us one step closer to mastering medical and anatomical terminology.

I will leave you, but I will leave you with a challenge.

Can you figure out what these terms mean based on today's video?

Let us know your answers in the comments below.

Now, another challenge.

Click on the subscribe button on our YouTube channel.

There will be more videos like this one coming up so we don't want you to miss a beat.

And that's a wrap for this installment of our series on Medical Terminology for Healthcare

Professionals.

We’ll see you next time when we will be looking at some terminology related to the

cardiovascular system – an episode that will touch your heart.

I'll see you there!